ROCKLAND — A Maine State Prison inmate who took two people hostage there in 2008 has been convicted of all 11 charges stemming from the incident.

Michael Chasse was convicted Friday following a two-week trial.

Chasse, who acted as his own lawyer, spent two days on the witness stand.

Chasse said he had unknowingly eaten a paper containing LSD on June 30, 2008, the day he took a prison librarian and another inmate hostage, using a makeshift knife.

He also said he was suffering from post-traumatic stress because of spending so many years in the prison segregation unit. The jury found him guilty of kidnapping, elevated aggravated assault and other charges.

Chasse was serving time for attacking the brother of former Sen. William Cohen and for an escape.